In the related art, as a bearing for a high-speed rotating body, a radial bearing which is used to be attached to surround a rotary shaft is known. As such a radial bearing, a radial foil bearing is well known, which includes a thin sheet-like top foil which forms a bearing surface, a back foil which elastically supports the top foil, and a cylindrical bearing housing which accommodates the top foil and the back foil. As the back foil of the radial foil bearing, a bump foil in which a thin sheet is formed into a wave shape is mainly used.
In general, in such a radial foil bearing, in order to prevent the top foil or the back foil from being detached from the bearing housing, one end (a toe portion) of the top foil or the back foil is directly connected to the bearing housing or is indirectly fixed thereto via a spacer, by spot welding.
Moreover, in order to perform a mechanical fixation instead of the welding, a radial foil bearing is also known which has a structure in which an end of the top foil or the back foil (bump foil) is bent by bending and the bent portion is engaged with an engagement groove formed on the bearing housing (for example, refer to Patent Documents 1 to 3).